Weed control is a very labor-intensive task in the agricultural sector, especially in the cultivation of organic crops where the use of chemicals is prohibited or restricted. Depending on the planted crop, a weed control in the immediate vicinity of the crop is required. This control generally takes place at an early growth state. At this point, crop plants as well as weeds are still very small and in close proximity to one another. In order to avoid damage to the crop plant, it is useful to employ selective methods. In organic farming (e.g., for carrots), this is done by labor-intensive, physically harmful manual work (employing what is known as “weeding floaters”: seasonal workers lying on their bellies on a platform and pulling weeds).
The present invention performs this work autonomously and also takes economical demands into account (rapid and precise work).
For special crops that have greater planting clearances (e.g., sugar beet, salad), conventional tractor attachment devices are able to identify individual crop plants and actuate corresponding tools in such a way that the area of the crop plant remains untouched. No selectivity is necessary for such a task. In other words, these systems do not examine the area to be worked; instead, the tool is steered “in blind mode” based on the known position of the crop plant. As a rule, the distance from the crop plant defines the precision demands.
However, none of the conventional devices is accurate enough to perform a weed control in the case of crops that feature small planting clearances (such as carrots). Here, a weed control in the immediate vicinity of the crop plant is necessary at an early stage and currently demands manual work.
German Patent No. DE 40 39 797 A1 describes a device for weed control in which an actuator for destroying the weeds is in permanent operation and is briefly interrupted only when a sensor detects a crop plant.